One way for improving an image contrast of a display device is usually to optimize the contrast of the display device through DFC digitalization. This is implemented by fine-tuning transmittance of a display panel and does not directly affect distribution of backlight brightness, and thus has no obvious effect on the improvement of the contrast of the display device. Meanwhile, the above way cannot reduce power consumption. Further, when a light source of the display device is turned on or off, light mixing phenomena may occur at some portion of a backlight source of the display device, thereby affecting the display effect of the display device.